U.S. patent application number 14/352952 was filed with the patent office on 2014-10-16 for fiber stacking device.
This patent application is currently assigned to KAO CORPORATION. The applicant listed for this patent is KAO CORPORATION. Invention is credited to Hiroshi Maruyama, Ryuji Matsunaga, Tomoyuki Motegi.
Application Number | 20140305570 14/352952 |
Document ID | / |
Family ID | 48140843 |
Filed Date | 2014-10-16 |
United States Patent
Application |
20140305570 |
Kind Code |
A1 |
Matsunaga; Ryuji ; et
al. |
October 16, 2014 |
FIBER STACKING DEVICE
Abstract
A rotating drum (1) has a collecting/stacking recess (2) in the
outer peripheral surface thereof, and includes: a drum body (3);
and an air-permeable porous member (4) that forms the bottom
surface (2A) of the collecting/stacking recess (2). The porous
member (4) is sandwiched between: an outer shaping member (6)
arranged so as to oppose the bottom surface (2A); and an inner
shaping member (7) arranged between the porous member (4) and the
drum body (3). Both the shaping members (6, 7) are arranged so as
to overlap the porous member (4). Each shaping member (6, 7) has a
recess-bottom-surface corresponding section (6A, 7A) that overlaps
the bottom surface (2A) of the collecting/stacking recess (2) in a
planar view thereof, and that is constituted by: a plurality of
openings (65, 75) that penetrate the recess-bottom-surface
corresponding section (6A, 7A) in the thickness direction; and an
opening defining section (60, 70) that partitions and forms the
openings (65, 75). The opening defining section (70) of the inner
shaping member (7) corresponds to the opening defining section (60)
of the outer shaping member (6).
Inventors: |
Matsunaga; Ryuji;
(Utsunomiya-shi, JP) ; Maruyama; Hiroshi;
(Utsunomiya-shi, JP) ; Motegi; Tomoyuki;
(Haga-gun, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KAO CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
KAO CORPORATION
|
Family ID: |
48140843 |
Appl. No.: |
14/352952 |
Filed: |
October 12, 2012 |
PCT Filed: |
October 12, 2012 |
PCT NO: |
PCT/JP2012/076505 |
371 Date: |
April 18, 2014 |
Current U.S.
Class: |
156/62.2 ;
264/101; 425/405.1 |
Current CPC
Class: |
A61F 13/15658 20130101;
A61F 2013/15926 20130101; D04H 1/736 20130101; A61F 13/15577
20130101; A61F 13/15617 20130101; D04H 1/44 20130101; D04H 1/732
20130101; A61F 2013/15943 20130101; A61F 13/15626 20130101; A61F
2013/15991 20130101 |
Class at
Publication: |
156/62.2 ;
425/405.1; 264/101 |
International
Class: |
D04H 1/44 20060101
D04H001/44; A61F 13/15 20060101 A61F013/15 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2011 |
JP |
2011-229421 |
Claims
1. A fiber stacking device comprising a rotating drum that has a
collecting/stacking recess in an outer peripheral surface thereof,
wherein the rotating drum forms a shaped product by stacking a
shaped-product material by sucking the material with a bottom
surface of the collecting/stacking recess, wherein: the rotating
drum includes a drum body, and an air-permeable porous member that
forms the bottom surface of the collecting/stacking recess; the
porous member is sandwiched between an outer shaping member
arranged so as to oppose the bottom surface of the
collecting/stacking recess, and an inner shaping member arranged
between the porous member and the drum body; both the shaping
members are arranged so as to overlap the porous member; each of
the shaping members has a recess-bottom-surface corresponding
section that overlaps the bottom surface of the collecting/stacking
recess in a planar view of the collecting/stacking recess; each the
recess-bottom-surface corresponding section is constituted by a
plurality of openings that penetrate the recess-bottom-surface
corresponding section in the thickness direction, and an opening
defining section that partitions and forms the openings; and the
opening defining section of the inner shaping member corresponds to
the opening defining section of the outer shaping member.
2. The fiber stacking device according to claim 1, wherein the
opening defining section of each the shaping member is
air-impermeable.
3. The fiber stacking device according to claim 1, wherein the
porous member includes an air-impermeable section in a section
corresponding to the opening defining section of the outer shaping
member or the inner shaping member,
4. The fiber stacking device according to claim 3, wherein the
air-impermeable section is formed by joining the porous member with
the outer shaping member and the inner shaping member.
5. The fiber stacking device according to claim 3, wherein the
air-impermeable section is formed by: (1) a welding method in which
sections to be joined in the porous member, the outer shaping
member, and the inner shaping member are molten by heat, and the
molten sections are directly fused together; or (2) a method in
which the porous member is joined with the outer shaping member and
the inner shaping member by means of an adhesive.
6. The fiber stacking device according to claim 3, wherein the
porous member includes an opening-defining-section corresponding
section in a section corresponding to the opening defining section,
either: the entire area of the opening-defining-section
corresponding section constitutes the air-impermeable section; or
only a portion of the opening-defining-section corresponding
section constitutes the air-impermeable section, and the
opening-defining-section corresponding section, as a whole, has low
air permeability that is lower than the air permeability of
sections, in the porous member, other than the
opening-defining-section corresponding section.
7. The fiber stacking device according to claim 1, wherein the
plurality of the openings disposed in the outer shaping member are
in one-to-one correspondence with the plurality of the openings
disposed in the inner shaping member.
8. The fiber stacking device according to claim 7, wherein, in a
planar view of the collecting/stacking recess, the opening disposed
in the outer shaping member and the opening disposed in the inner
shaping member that overlap one another are congruent or similar to
one another in terms of planar-view shape.
9. The fiber stacking device according to claim 1, wherein the
opening defining section of each the shaping member is constituted
by linear members extending along the bottom surface of the
collecting/stacking recess.
10. The fiber stacking device according to claim 9, wherein the
width of the linear member of the outer shaping member is different
from the width of the linear member of the inner shaping member
that overlaps the linear member of the outer shaping member in a
planar view of the collecting/stacking recess.
11. The fiber stacking device according to claim 1, wherein the
outer shaping member is fixed to the inner shaping member by means
of: a plurality of bolt holes made in the opening defining section
in the recess-bottom-surface corresponding section; and bolts
inserted in the respective bolt holes.
12. The fiber stacking device according to claim 1, wherein: the
drum body has a recess-bottom-surface corresponding section that
overlaps the bottom surface of the collecting/stacking recess in a
planar view of the collecting/stacking recess; the
recess-bottom-surface corresponding section is constituted by a
plurality of through holes that penetrate the recess-bottom-surface
corresponding section in the thickness direction, and
air-impermeable ribs each located between the two adjacent through
holes; and in a planar view of the collecting/stacking recess, the
ribs overlap the opening defining sections of the respective
shaping members.
13. The fiber stacking device according to claim 1, wherein the
bottom surface of the collecting/stacking recess has a flat
form.
14. A method for manufacturing an absorbent core by using the fiber
stacking device according to claim 1, the absorbent core
manufacturing method comprising: a fiber stacking step of sucking
and stacking, in the collecting/stacking recess of the rotating
drum, an absorbent-core material supplied on an air stream.
15. A method for manufacturing an absorbent article that includes
an absorbent core and a sheet material to which the absorbent core
is fixed, the absorbent article manufacturing method comprising: a
step of fixing, onto the sheet material, the absorbent core
obtained by executing the manufacturing method according to claim
14.
Description
TECHNICAL FIELD
[0001] The present invention relates to a fiber stacking device
that includes a rotating drum having a collecting/stacking recess
in the outer peripheral surface thereof, and that is used for
obtaining shaped products (absorbent cores) having predetermined
shapes by stacking shaped-product materials--e.g. fiber materials,
such as pulp, and water-absorbent polymers--in the
collecting/stacking recess.
BACKGROUND ART
[0002] A known example of a device for manufacturing absorbent
cores used for sanitary products (absorbent articles), such as
disposable diapers and sanitary napkins, is a fiber stacking device
that includes a rotating drum having a collecting/stacking recess
in the outer peripheral surface thereof, wherein: a shaped-product
material, such as pulp, is supplied to the outer peripheral surface
of the rotating drum in a dispersed, airborne state while rotating
the rotating drum; the shaped-product material is stacked in the
collecting/stacking recess by suction from the bottom surface of
the collecting/stacking recess; and the fiber stack in the
collecting/stacking recess is released from the collecting/stacking
recess by suction from a suction means arranged in opposition to
the collecting/stacking recess, and is transferred onto the suction
means.
[0003] As an example of a rotating drum for the aforementioned
fiber stacking device, Patent Literature 1 discloses a rotating
drum including a porous air-permeable member, such as a wire mesh,
that forms the bottom surface of a collecting/stacking recess, and
masking members attached onto the air-permeable member so as to be
movable in a predetermined direction, whereby an absorbent core
having a desired shape and basis weight distribution can be
manufactured by moving the masking members.
[0004] Patent Literature 2 discloses a rotating chum including an
air-permeable porous plate that has a multitude of suction pores
and that forms the bottom surface of a collecting stacking recess,
and a honeycomb structure rectifier that is for rectifying the flow
of air and that is arranged integrally to the porous plate on the
inside thereof. According to Patent Literature 2, the use of such a
rotating drum stabilizes the profile of the absorbent core and
reduces unevenness in weight of the absorbent core.
[0005] Patent Literature 3 discloses a rotating drum wherein a
plurality of protrusions, each protruding outward in the drum's
radial direction and elongated in the drum's circumferential
direction, are formed over the entire area of an air-permeable
bottom surface of a collecting/stacking recess. The protrusions are
arranged continuously or intermittently in the circumferential
direction, and arranged so as to be separated from one another by a
predetermined distance in the axial direction of the drum.
According to Patent Literature 3, by using such a rotating drum,
shaped-product materials are stacked in the recessed spaces other
than the protrusions, and thus, the final shaped product (absorbent
core) has a plurality of intermittently arranged low-rigidity
sections formed by the protrusions, and is thus provided with
uniform rigidity and excellent flexibility and is capable of
efficiently absorbing body fluid with the entire area thereof.
[0006] Patent Literature 4 discloses a rotating drum wherein a
spacing member having a plurality of openings, and a gas flaw rate
regulating layer having a plurality of openings, are layered in
this order on the inner side of a web layer that forms the bottom
surface of a collecting/stacking recess (i.e., on the side where
shaped-product materials are not stacked). According to Patent
Literature 4, the bottom surface (i.e., the web layer) of the
collecting/stacking recess is not flat, but the bottom surface has
recesses in the central section in the drum's width direction, and
thus, sections in the shaped product that correspond to the
recesses can be made into high basis-weight sections in which the
amount of shaped-product materials stacked is greater compared to
other sections.
CITATION LIST
Patent Literature
[0007] Patent Literature 1: U.S. Pat. No. 6,330,735 B1
[0008] Patent Literature 2: US 2009281511 A1
[0009] Patent Literature 3: US 2006105075 A1
[0010] Patent Literature 4: EP 0226939 A2
SUMMARY OF INVENTION
Technical Problem
[0011] In the fiber stacking devices configured as above, a fiber
stack obtained by stacking shaped-product materials in the
collecting/stacking recess of the rotating drum is released from
the collecting/stacking recess by suction from a suction means
arranged in opposition to the collecting/stacking recess and is
transferred onto the suction means. At the time of
releasing/transferring, there are cases where the fiber stack gets
caught in a gap etc. formed between constituent members in the
collecting/stacking recess, and cannot be released smoothly from
the collecting/stacking recess, possibly causing faulty
transferring of the fiber stack. Faulty fiber-stack transferring
not only decreases manufacturing efficiency, but may also give rise
to problems--such as loss of shape of the fiber stack and
misalignment in transferring position--that lead to degradation in
quality of the shaped product, which is the final product. Thus, it
is desired to prevent the occurrence of such problems.
Solution to Problem
[0012] The present invention provides a fiber stacking device
including a rotating drum that has a collecting/stacking recess in
an outer peripheral surface thereof, wherein the rotating drum
forms a shaped product by stacking a shaped-product material by
sucking the material with a bottom surface of the
collecting/staking recess, wherein: the rotating drum includes a
drum body, and an air-permeable porous member that forms the bottom
surface of the collecting/stacking recess; the porous member is
sandwiched between an outer shaping member arranged so as to oppose
the bottom surface of the collecting/stacking recess, and an inner
shaping member arranged between the porous member and the drum
body; both of the shaping members are arranged so as to overlap the
porous member; each of the shaping members has a
recess-bottom-surface corresponding section that overlaps the
bottom surface of the collecting/stacking recess in a planar view
of the collecting/stacking recess; each recess-bottom-surface
corresponding section is constituted by a plurality of openings
that penetrate the recess-bottom-surface corresponding, section in
the thickness direction, and an opening defining section that
partitions and forms the openings; and the opening defining section
of the inner shaping member corresponds to the opening defining
section of the outer shaping member.
[0013] The present invention also provides a method for
manufacturing an absorbent core by using the aforementioned fiber
stacking device, the absorbent core manufacturing method involving:
a fiber stacking, step of sucking and stacking, in the
collecting/stacking recess of the rotating drum, an absorbent-core
material supplied on an air stream.
[0014] The present invention also provides a method for
manufacturing an absorbent article that includes an absorbent core
and a sheet material to which the absorbent core is fixed, the
absorbent article manufacturing method involving; a step of fixing,
onto the sheet material, the absorbent core obtained by executing
the aforementioned manufacturing method.
Advantageous Effects of Invention
[0015] With the fiber stacking device of the present invention,
fiber stacks in the collecting stacking recess of the rotating drum
can be released smoothly, and faulty transferring is less prone to
occur, and thus, shaped products with a desired shape can be
manufactured efficiently. Further, with the absorbent core
manufacturing method of the present invention, it is possible to
efficiently manufacture high-quality absorbent cores with no loss
of shape, etc.
BRIEF DESCRIPTION OF DRAWINGS
[0016] [FIG. 1] FIG. 1 is a schematic perspective view of an
embodiment of a fiber stacking device of the present invention.
[FIG. 2] FIG. 2 is a perspective view illustrating a rotating drum
of the fiber stacking device illustrated in FIG. 1.
[0017] [FIG. 3] FIG. 3 is to diagram explaining the construction of
the rotating drum illustrate FIG. 2.
[0018] [FIG. 4] FIG. 4 is a cross-sectional view illustrating a
cross section of the outer peripheral surface, and its vicinity, of
the rotating drum illustrated in FIG. 2, taken along the width
direction of the drum.
[0019] [FIG. 5] FIG. 5 is a plan view illustrating, in an enlarged
state, a portion of a surface of the rotating drum illustrated in
FIG. 2 on the opposite side from the bottom surface of the
collecting/stacking recess (i.e., a portion of the surface opposing
the drum body).
[0020] [FIG. 6] FIG. 6 is a cross-sectional view (corresponding to
FIG. 4) illustrating a state where a shaped-product material has
bean stacked in the collecting/stacking recess of the rotating drum
illustrated in FIG. 2.
[0021] [FIG. 7] FIG. 7(a) is a perspective view illustrating a
fiber stack released from the collecting/stacking recess
illustrated in FIG. 6, and FIG. 7(b) is a cross-sectional view
taken along line I-I of FIG. 7(a).
[0022] [FIG. 8] FIG. 8 is a cross-sectional view (corresponding to
FIG. 4) illustrating a cross section of the outer peripheral
surface, and its vicinity, of another embodiment of a rotating drum
according to the present invention, taken along the width direction
of the drum.
[0023] [FIG. 9] FIGS. 9(a) and 9(b) are plan views illustrating
examples of air-impermeable sections in the rotating drum
illustrated in FIG. 8.
[0024] [FIG. 10] FIG. 10 is a perspective view of a portion of a
main part of yet another embodiment of a rotating drum according to
the present invention.
[0025] [FIG. 11] FIG. 11 is a diagram explaining the construction
of the main part of the rotating drum illustrated in FIG. 10.
[0026] [FIG. 12] FIG. 12 is diagram, corresponding to FIG. 11, of a
main part of yet another embodiment of a rotating drum according to
the present invention.
[0027] [FIG. 13] FIG. 13 is a diagram explaining the construction
of a main part of yet another embodiment of a rotating drum
according to the present invention.
[0028] [FIG. 14] FIG. 14 is a diagram explaining the construction
of a rotating drum of a fiber stacking device outside the scope of
the present invention.
[0029] [FIG. 15] FIG. 15(a) is a cross-sectional view illustrating
a state where a shaped-product material has been stacked in the
collecting/stacking recess of the rotating drum illustrated in FIG.
14, FIG. 15(b) is a diagram explaining a step for releasing a fiber
stack from the collecting/stacking recess illustrated in FIG. 15(a)
and transferring the fiber stack onto a suction means, and FIG.
15(c) is an enlarged cross-sectional view schematically
illustrating a portion of FIG. 15(b) in an enlarged state.
DESCRIPTION OF EMBODIMENTS
[0030] The present invention relates to a fiber stacking device in
which fiber stacks in a collecting/stacking recess of a rotating
drum can be released smoothly and faulty transferring is less prone
to occur, and thus, shaped products with a desired shape can be
manufactured efficiently.
[0031] The fiber stacking device of the present invention will be
described below according to a preferred embodiment thereof with
reference to the drawings. FIG. 1 illustrates a fiber stacking
device 10 which is an embodiment of the fiber stacking device of
the present invention. FIGS. 2 to 4 illustrate a rotating, drum 1
provided to the fiber stacking device 10. The fiber stacking device
10 includes a rotating drum 1 that has a collecting/stacking recess
2 in the outer peripheral surface thereof, wherein the rotating
drum 1 forms a shaped product by stacking a shaped-product material
by sucking the material with the bottom surface 2A of the
collecting/stacking recess 2.
[0032] As illustrated in FIG. 1, the fiber stacking device 10
includes: the aforementioned rotating drum 1 driven to rotate in
the direction of arrow R1; a duct 11 that supplies shaped-product
materials to the other peripheral surface of the rotating drum 1; a
transfer roller 12 that is driven to rotate in the direction of
arrow R2, and that is arranged obliquely below the rotating drum 1;
and a vacuum conveyor (not illustrated) arranged below the transfer
roller 12. The vacuum conveyor of the fiber stacking device 10 is
constructed like an ordinary vacuum conveyor employed in this type
of fiber stacking device, and includes: an endless, air-permeable
belt that is spanned between a drive roller and a driven roller;
and a vacuum box arranged at a position opposing the transfer
roller 12 across the air-permeable belt.
[0033] Further, in the fiber stacking device 10: a vacuum box 13 is
provided between the duct 11 and the transfer roller 12 in the
circumferential direction of the rotating drum 1; a mesh belt 14 is
arranged so as to pass between the vacuum box 13 and the rotating
drum 1 and between the transfer roller 12 and the rotating drum 1;
and windshield plates 15 are provided close to the outer peripheral
surface of the transfer roller 12.
[0034] Below, the relating drum 1, which is the main characteristic
part of the fiber stacking device 10, will be described. As
illustrated in FIGS. 2 to 4, the rotating drum of the present
embodiment has, in its outer peripheral surface, a
collecting/stacking recess 2 in which shaped-product materials are
stacked, and includes: a drum body 3; and an air-permeable porous
member 4 that forms the bottom surface 2A of the
collecting/stacking recess 2 and in which a multitude of
air-permeation holes are formed. The collecting/stacking recess 2
is formed continuously in the outer peripheral surface or the
rotating drum 1 along the entire length in the circumferential
direction. The porous member 4 has a flat form; thus, tie bottom
surface 2A of the collecting/stacking recess 2 formed by the porous
member 4 has a flat form, and substantially has no projections and
recesses. Stated differently. the sections of the bottom surface 2A
that correspond to openings 65 (i.e., spaces surrounded by linear
members 61, 62) in a later-described outer shaping member 6
(recess-bottom-surface corresponding section 6A) (i.e., sections
that overlap the aforementioned corresponding sections in a planar
view of the collecting/stacking recess 2) are flat. It should be
noted that, herein, "projections and recesses" refer to projections
and recesses which affect the amount of shaped-product materials
stacked (i.e., projections and recesses which are intentionally
formed in order to partially differentiate the stacking amount),
and do not include fine projections and recesses which do not
affect the amount of shaped-product materials stacked.
[0035] The drum body 3 is made of a stiff, metal tube, and has, in
the central section in the drum's width direction (i.e., the
direction of the rotation axis of the rotating drum; the direction
indicated by symbol X in the figure), a recess-bottom-surface
corresponding section 31 that overlaps the bottom surface 2A of the
collecting/stacking recess 2 in a planar view thereof. Herein,
"planar view" refers to a view in which an object
(collecting/stacking recess, etc.) is viewed from the outside along
the direction of the normal to the outer peripheral surface of the
rotating drum 1 (i.e., along a direction orthogonal to the rotation
direction the rotating drum 1). The recess-bottom-surface
corresponding section 31 of the drum body 3 is constituted by a
plurality of through openings 32 (eight in the embodiment
illustrated in FIG. 3) that penetrate the recess-bottom-surface
corresponding section 31 in the thickness direction, and
air-impermeable ribs 33 each located between two adjacent through
openings 32, 32. By being provided with the through openings 32,
the recess-bottom-surface corresponding section 31, as a whole, is
air-permeable. The plurality of through openings 32 are formed
along the circumferential direction of the drum body 3 at
predetermined intervals. Between two through openings 32, 32
adjacent to one another in the circumferential direction, an
air-impermeable rib 33 is funned so as to extend in the drum's
width direction X. The ribs 33 mainly serve to improve the strength
of the drum body 3 itself and to improve the strength of the bottom
section of the collecting/stacking recess 2.
[0036] The porous member 4 conveys vacuum air, which is generated
from inside the drum, to the outside of the drum, and holds
shaped-product materials, such as pulp, that are carried on the
vacuum air. The porous member 4 itself (i.e., the member that
defines the air-permeation holes) is made of an air-impermeable or
sparingly air-permeable material, but a multitude of fine
air-permeation holes are formed over the entire area of the porous
member 4, so thus, the air-permeation holes function as suction
holes for sucking the shaped-product materials while the
collecting/stacking recess 2 passes over a space, in the rotating
drum 1, that is maintained at negative pressure. The porous member
4 may have, as the air-permeation holes, e.g. circular holes with a
diameter of about 0.2 to 0.6 mm formed at a pitch or about 0.4 to
1.5 rum in a staggered pattern, Examples of air-impermeable
materials include stainless steel, iron, aluminum, and polymer
materials. An example of a sparingly air-permeable material
includes material in which micro-holes are made in a member made of
an air-impermeable material. As the porous member 4, it is possible
to use a metal or resin mesh, or a porous metal plate or resin
plate in which a multitude of fine holes are formed in a metal or
resin plate by etching or punching. As an example of a porous metal
plate or resin plate for forming the porous member 4, it is
possible to use a plate in which a multitude of fine holes are
formed, for example, by punching or etching in a metal or resin
plate stainless steel plate) with a thickness of about 0.1 to 0.5
mm. As described above, in the present embodiment, the bottom
surface 2A of the collecting/stacking recess 2 has a flat form; so,
the porous member 4 that forms the flat-form bottom surface 2A
substantially has no projections and recesses, and thus, the
apparent thickness of the porous member 4 is uniform over the
entire area in the circumferential direction of the rotating drum
1.
[0037] As illustrated in FIGS. 2 to 4, the rotating drum 1 of the
present embodiment also includes ring members 5 that form the
respective inner-side surfaces 2B of the collecting/stacking recess
2, in addition to the drum body 3 and the porous member 4. The ring
members 5 define the length of the collecting/stacking recess 2 in
the drum's width direction X (i.e., the width of the
collecting/stacking recess 2), and are arranged on the respective
side sections, in the width direction, of the outer peripheral
surface of the rotating drum 1 with the collecting/stacking recess
2 sandwiched between the ring members 5. The distance between the
ring member 5 on the side of one widthwise side section and the
ring member 5 on the side of the other side section (i.e. the
distance between the pair of right and left ring members)
constitutes the width of the collecting/stacking recess 2. Further,
the inner end surface of the ring member 5 formed along the
circumferential direction of the rotating drum 1 forms a portion of
the inner-side surface 2B of the collecting/stacking recess 2, and
is an element that determines the thickness of the
collecting/stacking recess 2. The positions for attaching the
respective ring members 5 (the distance between the pair of right
and left ring members) and the thickness thereof (the height or the
inner end surface) are determined with consideration given to, for
example, the width of the shaped product (fiber stack) and the
amount of shaped-product materials to be stacked. The ring member 5
is air-impermeable and is made, for example, of a metal plate such
as a stainless steel plate, and its thickness is, for example,
about 2 to 12 mm.
[0038] One of the main features of the rotating drum 1 of the
present embodiment is that the porous member 4, which forms the
bottom surface 2A of the collecting/stacking recess 2, is
sandwiched between an outer shaping member 6 arranged so as to
oppose the bottom surface 2A of the collecting/stacking recess 2,
and an inner shaping member 7 arranged between the porous member 4
and the drum both 3, as illustrated in FIGS. 3 and 4. Both of the
shaping members 6, 7 are arranged so as to overlap the porous
member 4, as illustrated in FIGS. 3 and 4, and no other member is
arranged between the outer shaping member 6 and the porous member
4, and between the inner shaping member 7 and the porous member 4.
The length in the drum's width direction X (i.e., the width) of
each of the outer shaping member 6 and the inner shaping member 7
is the same as that of the porous member 4, and each shaping member
has, in the central section in the drum's width direction X, a
recess-bottom-surface corresponding section 6A, 7A that overlaps
the bottom surface 2A of the collecting/stacking recess 2 in a
planar view thereof (cf. FIG. 3). Here, "planar view" has the
aforementioned meaning.
[0039] As illustrated in FIGS. 3 and 4, the recess-bottom-surface
corresponding sections 6A, 7A of the respective shaping members 6,
7, which overlap the bottom surface 2A of the collecting/stacking
recess 2 in a planar view of the collecting/stacking recess 2, are
each constituted by a plurality of openings 65, 75 that penetrate
the recess-bottom-surface corresponding section 6A, 7A in the
thickness direction, and an opening defining section 60, 70 that
partitions and forms the openings 65, 75.
[0040] In the present embodiment, as illustrated in FIGS. 3 and 4,
the opening defining sections 60, 70 of the respective shaping
members 6, 7 are each constituted by linear members 61, 62, 71, 72
extending along the bottom surface 2A of the collecting/stacking
recess 2 (i.e., along the outer peripheral surface of the rotating
drum 1). Herein, "extend along the bottom surf 2A of the
collecting/stacking recess 2" refers both to cases where the
opening defining sections 60, 70 (the linear members 61, 62, 71,
72) are in contact with the bottom surface 24 (the porous member 4)
and cases where they are not in contact with the bottom surface
2A.
[0041] More specifically, as illustrated in FIG. 3, the opening
defining section 60 of the outer shaping member 6 includes a
plurality of width-wise linear members 61 that, in a planar view,
are each in a straight line extending in the drum's width direction
X, and a plurality of circumference-wise linear members 62 (four in
the present embodiment) that, in a planar view, are each in a
straight line orthogonal to the plurality of width wise linear
members 61. The opening defining section 60 of the outer shaping
member 6 is formed in a lattice pattern, in planar view, by the
linear members 61, 62. The openings 65 in the outer shaping member
6 are located at the respective cells of the lattice and each have
a rectangular shape in planar view.
[0042] Further, as illustrate in FIG. 3, the opening defining
section 70 of the inner shaping member 7 includes a plurality of
width-wise linear members 71 that, in a planar view, are each in a
straight line extending in the drum's width direction X, and a
plurality of circumference-wise linear members 72 (four in the
present embodiment) that, in a planar view, are each in a straight
line orthogonal to the plurality of width-wise linear members 71.
The opening defining section 70 of the inner shaping member 7 is
formed in a lattice pattern, in planar view, by the linear members
71, 72, The openings 75 in the outer shaping member 6 are located
at the respective cells of the lattice and each have a rectangular
shape in planar view.
[0043] The collecting/stacking recess 2 is partition ad by the
opening defining section 60 of the outer shaping member 6 into a
plurality of recesses that correspond to the plurality of openings
65 of the outer shaping member 6. Each recess is constituted by the
porous member 4 (the bottom surface 2A), and side walls that
consist of the opening defining section 60 and that are formed
upright from the porous member 4 in the direction of the normal;
and the entire porous member 4 forms a suction section that sucks
shaped-product materials. The space in each recess surrounded by
the side walls consisting of the opening defining section 60 (i.e.,
the inner space of each recess) is the opening 65.
[0044] The opening defining sections 60, 70 (the linear members 61,
62, 71, 72) of the respective shaping members 6, 7 are made of an
air-impermeable or sparingly air-permeable material, like the
porous member 4, and are air-impermeable. Herein, "air
impermeability" of the opening defining sections 60, 70 refers to a
property that makes vacuum air, which is generated from inside the
drum, hard to permeate through the members (the opening defining
sections 60, 70), and encompasses cases where vacuum air is
completely prevented from permeating therethrough (i.e., cases
where there is no air permeability) and also cases where the member
as some air permeability, albeit low, but cannot adsorb
shaped-product materials (pulp, etc.), which are in a dispersed
airborne state outside the drum, by the vacuum air that permeates
through the member (i.e., cases where there is substantially no air
permeability). Unless otherwise stated, the aforementioned
explanation applies to the description "air impermeability
(air-impermeable)" in the present Description; for example, the air
impermeability of the porous member 4 itself (i.e., the member that
defines the air-permeation holes) has the same meaning as the air
impermeability of the opening defining sections 60, 70. As
described above, the opening defining sections 60, 70 (the linear
members 61, 62, 71, 72) of the recess-bottom-surface corresponding
sections 6A, 7A of the respective shaping members 6, 7 are
air-impermeable, but because of the plurality of openings 65, 75
that allow the passage of air, the recess-bottom-surface
corresponding sections, as a whole, have sufficient on permeability
for sucking and stacking the shaped-product materials.
[0045] Whether to use an air-impermeable or sparingly air-permeable
material as the material for forming the opening defining sections
60, 70 (the linear members 61, 62, 71, 72) may be chosen, as
appropriate, depending on the use etc. of the shaped product
(absorbent core) to be manufactured. Inventors found that, in cases
where the air permeability of the opening defining sections 60, 70
is lower than the air permeability of the bottom surface 2A (the
porous member 4) of the collecting/stacking recess 2, fiber
stacking properties are improved and shaped-product materials can
be stacked smoothly in the collecting stacking recess 2, and also,
transferring properties are improved and the fiber stack in the
collecting/stacking recess 2 can be transferred smoothly, compared
to cases where the air permeability of the opening defining
sections and that of the porous member are the same. Thus, it is
preferable to select the material for forming the opening defining
sections 60, 70 such that the air permeability of the defining
sections 60, 70 becomes lower than that of the bottom surface 2A
(the porous member 4) of the collecting/stacking recess 2.
[0046] In the present embodiment, the sections of the outer shaping
member 6 other than the recess-bottom-surface corresponding section
6A--i.e., the side sections 6B, 6B of the outer shaping member 6 in
the drum's width direction X--constitute ring-member corresponding
sections that overlap the respective ring members 5 in a planar
view of the outer peripheral surface of the rotating drum 1. The
length in the drum's width direction X (i.e., the width) of each
side section 60 of the outer shaping member 6 is the same as the
width of each ring member 5. As illustrated in FIG. 4, as regards
each side section 6B of the outer shaping member 6, the inner end
surface thereof along the circumferential direction of the rotating
drum 1 forms a surface that is flush with the inner end surface of
the ring member 5, and forms the inner-side surface 2B of the
collecting/stacking recess 2 together with the ring member 5. The
side sections 6B of the outer shaping member 6 are made of an
air-impermeable or sparingly air-permeable material like the
recess-bottom-surface corresponding section 6A (the opening
defining section 60), and is air-impermeable like the opening
defining section 60.
[0047] Further, in the present embodiment, the sections at the
inner shaping member 7 other than the recess-bottom-surface
corresponding section 7A--i.e., the side sections 7B, 7B of the
inner shaping member 7 in the drum's width direction X--constitute
ring-member corresponding sections that overlap the respective ring
members 5 in a planar view of the outer peripheral surface of the
rotating drum 1. The length in the drum's width direction X (i.e.,
the width) of each side section 7B of the inner shaping member 7 is
the same as the width of each ring member 5, and is thus the same
as the width of the side section 6B of the outer shaping member 6.
As illustrated in FIG. 3, as regards each side section 7B of the
inner shaping member 7, the inner end surface thereof along the
circumferential direction of the rotating drum 1 forms a surface
that is flush with the inner end surface of the ring member 5 and
the inner end surface of the side section 6B or the Outer shaping
member 6. The side sections 7B of the inner shaping member 7 are
made of an air-impermeable or sparingly air-permeable material like
the recess-bottom-surface corresponding section 7A (the opening
defining section 70), and is air-impermeable like the opening
defining section 70.
[0048] The thickness of the recess-bottom-surface corresponding
section 6A of the outer shaping member 6 is preferably 1 mm or
greater and more preferably 2 mm or greater, and preferably 30 mm
or less and more preferably 15 mm or less. More specifically, the
thickness of the recess-bottom-surface corresponding section 6A is
preferably from 1 to 30 mm and more preferably from 2 to 15 mm. The
thickness of the side sections 6B may be set to be similar to the
thickness of the recess-bottom-surface corresponding section 6A.
The thickness of the recess-bottom-surface corresponding section 7A
of the inner shaping member 7 is preferably 1 mm or greater and
more preferably 2 mm or greater, and preferably 30 mm or less and
more preferably 15 mm or less. More specifically, the thickness of
the recess-bottom-surface corresponding section 7A is preferably
from 1 to 30 mm and more preferably from 2 to 20 mm. The thickness
of the side sections 7B may be set to be similar to the thickness
of the recess-bottom-surface corresponding section 7A.
[0049] The opening defining section 70 of the inner shaping member
7 corresponds to the opening defining section 60 of the outer
shaping member 6. In other words, the opening defining section 70
of the inner shaping member 7 is always arranged in opposition to
the opening defining section 60 of the outer shaping member 6. As
illustrated in FIGS. 3 and 4, the present embodiment, the opening
defining section 70 (each linear member 71, 72) of the inner
shaping member 7 is in one-to-one correspondence with the opening
defining section 60 (each linear member 61, 62) of the outer
shaping member 6. It should be noted that the correspondence
between the two is not limited to the aforementioned one-to-one
correspondence, and the inner shaping member 7 may have an opening
defining section 70 (linear members 71, 72) not corresponding to
the opening defining section 60 (linear members 61, 62) of the
outer shaping member 6.
[0050] As illustrated in FIGS. 3 and 4, in the present embodiment,
the plurality of openings 65 in the outer shaping member 6 are in
one-to-one correspondence with the plurality of openings 75 in the
inner shaping member 7. In other words, in a planar view of the
collecting/stacking recess 2, one opening 65 overlaps one opening
75. Further, one opening 65 and one opening 75 corresponding
therewith (i.e., the openings 65, 75 that overlap one another in a
planar view of the collecting/stacking recess 2) are similar to one
another in terms of planar-view shape. In the present embodiment,
the ratio of similitude of the opening 75 to the corresponding
opening 65 is 1 and so, the opening 65 and the opening 75 are
congruent in terms of planar-view shape.
[0051] As described above, in the present embodiment, the openings
65 and the openings 75 are in one-to-one correspondence, and the
openings 65, 75 in a corresponding relationship are congruent in
terms of planar-view shape. Thus, as a matter of course, in the
opening defining sections 60, 70 that partition and form the
respective openings 65, 75, the number of width-wise linear members
61 and width-wise linear members 71 (the onto bet arranged) is the
same, and also, the number of circumference-wise linear members 62
and circumference-wise linear members 72 (the number arranged) is
the same, and furthermore, the width (i.e., the length in the
direction orthogonal to the linear direction) of the linear members
61, 62 of the outer shaping member 6 is the same as the width of
the linear members 71, 72 of the inner shaping member 7 that
overlap the respective linear members 61, 62 in a planar view of
the collecting/stacking recess 2. In other words, the width W2 (cf.
FIG. 4) of each of the circumference-wise linear members 62--which
are in a straight line and which constitute the opening defining
section 60--is the same as the width W4 (c.f. FIGS. 4 and 5) of
each of the circumference-wise linear members 72--which are in a
straight line and which constitute the opening defining section
70--that are located right beneath the respective linear members 62
(i.e., on the drum body 3 side) across the porous member 4; and
also, the width W1 (not illustrated) of each of the width-wise
linear members 61--which are in a straight line and which
constitute the opening defining section 60--is the same as the
width W3 (cf. FIG. 5) of each of the width-wise linear members
71--which are in a straight line and which constitute the opening
defining section 70--that are located right beneath the respective
linear members 61 (i.e., on the drum body 3 side) across the porous
member 4. The width W1 of each width-wise linear member 61
constituting the opening defining section 60 and the width W2 of
each circumference-wise linear member 62 affect the shape of the
shaped product (the fiber stack), and are thus set as appropriate
depending on the use etc. of the shaped product; the width is
preferably 1 mm or greater and more preferably 2 mm or greater, and
preferably 10 mm or less and more preferably 8 mm or less. More
specifically, the width W1 and the width W2 are each preferably
from 1 to 10 mm and more preferably from 2 to 8 mm. The width W3 is
in the same range as the width W1 and the width W4 is in the same
range as the width W2. The widths W1 and W2 (and the widths W3 and
W4) may be the same or different from one another.
[0052] It should be noted that, in the present embodiment, the
widths (W1 to W4) of the respective linear members 61, 62, 71, 72
do not change and are constant along the thickness direction of the
linear members (i.e., the depth direction of the
collecting/stacking recess 2), as illustrated for linear members
62, 72 in FIG. 4. However, the widths may be varied along the
thickness direction, and, for example, may gradually increase or
decrease toward the porous member 4. In such cases, the width (W1
to W4) of each linear member 61, 62, 71, 72 refers to the width of
each linear member at the section closest to the porous member 4
(the bottom surface 2A) (the width of the section in contact if the
linear member is in contact with the porous member 4).
[0053] As described above, in the present embodiment, the
air-permeable porous member 4, which forms the bottom surface 2A of
the collecting/stacking recess 2, is sandwiched between the outer
shaping member 6 and the inner shaping member 7, which are each
constituted by a plurality of openings 65, 75 and an opening
defining section 60, 70 that partitions and farms the openings 65,
75. Thus, the strength of the bottom section of the
collecting/stacking recess 2 is improved and the bottom section is
less prone to deform, and the contact between the porous member 4
and the outer shaping member 6--which constitute the inside of the
collecting/stacking recess 2--is made tighter, and gaps are less
likely to be formed between the bottom surface 2A of the
collecting/stacking recess 2 and the opening defining section 60
(the linear members 61, 62) of the outer shaping member 6 located
on the bottom surface 2A, compared to cases where the bottom
section of the collecting/stacking recess is constituted only by
the porous member or cases where the bottom section of the
collecting stacking recess is constituted by two layers--i.e., the
porous member and a shaping member arranged on the side of one
surface of the porous member--as in the later-described rotating
drum 80 (cf. FIGS. 11 and 15). Thus, according to the rotating drum
1 of the present embodiment, the above-described faulty
transferring of fiber stacks, which is caused by the fiber stacks
getting caught in the aforementioned gaps, is less prone to occur,
and also, uniform slacking of shaped-product materials inside the
collecting/stacking recess 2 is promoted because the vacuum air for
carrying the shaped-product materials is rectified easily. Thus,
shaped products with good shape and without shape loss can be
manufactured efficiently.
[0054] FIGS. 14 and 15 illustrate a rotating drum 80 in which the
bottom section of a collecting/stacking recess 90 is constituted by
two layers: a porous member 82; and a shaping member 84 arranged on
the side of one surface of the porous member 82. The
air-impermeable shaping member 84, which inhibits the suction of
shaped-product materials from the bottom surface of the
collecting/stacking recess 90, is provided on the bottom surface of
the recess 90. In general, an "air-impermeable shaping member on
the bottom surface of a collecting/stacking recess" is employed
with the aim of, for example, partially differentiating the amount
of shaped-product materials to be stacked. Such a shaping member,
however, may cause faulty transferring of fiber stacks. This is
described in further detail in relation to the rotating drum 80. As
illustrated in FIG. 15(a), the rotating drum 80 has, in its outer
peripheral surface, a collecting/stacking recess 90 in which
shaped-product materials, such as pulp, are stacked. As illustrated
in FIG. 14, the rotating drum 80 includes: a drum body 81; an
air-permeable porous member 82 that forms the bottom surface of the
collecting/stacking recess 90 and in which a multitude of
air-permeation holes are formed; ring members 83 that form the
respective inner-side surfaces of the collecting/stacking recess 90
(i.e., the wall surfaces that extend in a direction intersecting
with the bottom surface); and a shaping member 84 that is provided
between the porous member 82 and the ring members 83 and that
partitions the collecting/stacking recess 90 into a plurality of
regions along the bottom surface direction. The section 84A, in the
shaping member 84, corresponding to the bottom surface of the
collecting/stacking recess 90 is formed in a lattice pattern by a
plurality of air-impermeable linear members 85 that, in a planar
view, are each in a straight line orthogonal to one another.
Openings 86 that penetrate the shaping member 84 in thickness
direction are formed at positions of the respective cells in the
lattice.
[0055] If the aforementioned rotating drum 80 is used and
shaped-product materials are stacked in the collecting/stacking
recess 90 by suction from the bottom surface of the
collecting/stacking recess 90 with a suction means (not
illustrated) according to an ordinary method, the shaped-product
materials are sucked and stacked in the openings 86 with higher
priority, because suction from the bottom surface is not performed
on the air-impermeable linear members 85. As a result, a fiber
stack 95 in which the amount of shaped-product materials stacked is
partially different is formed in the collecting/stacking recess 90,
as illustrated in FIG. 15(a). If this fiber stack 95 in the
collecting/stacking recess 90 is sucked by a vacuum conveyor 96
arranged in opposition to the collecting/stacking recess 90 in
order to release the fiber stack from the collecting/stacking
recess 90 and transfer it onto the vacuum conveyor 96 as
illustrated in FIG. 15(b), the shaped-product materials
constituting the fiber stack 95 may get caught in the gaps 87
formed between the porous member 82 and the linear members 85 as
illustrated in FIG. 15(c), which may prevent the smooth release of
the fiber stack 95 from the recess. Further, because there are a
multitude of gaps 87--which may inhibit the smooth release of the
fiber stack 95--formed in the collecting/stacking recess 90, faulty
transferring of the fiber stack 95 is prone to occur. Furthermore,
the gaps 87 disturb the rectification of vacuum air that is
generated from inside the rotating drum 80 and that is for carrying
the shaped-product materials, and may thus prevent the
shaped-product materials from being stacked uniformly and may cause
deformations in the shape of the fiber stack (the shaped product).
In contrast, the rotating drum 1 of the present embodiment has the
aforementioned construction (e.g., the bottom section of the
collecting/stacking recess 2 is constituted by three layers: the
porous member 4; and shaping members 6, 7 arranged on the side of
one surface of the porous member 4 and on the side of the other
surface thereof), and is thus superior to the aforementioned
rotating drum 80 in terms of for example, transferring properties
and shaping properties.
[0056] Further, as described above, in the present embodiment, the
width of each of the linear members 61, 62 of the outer shaping
member 6 is set to be equal to the width of each of the linear
members 71, 72 of the inner shaping member 7 that overlap the
respective linear members 61, 62 in a planar view of the collecting
stacking recess 2 (i.e., W1=W3 and W2=W4), However, excellent
results can be obtained, even if the widths of the linear members
are made different. More specifically, it the widths W3 and W4 of
the linear members 71, 72 or the inner shaping member 7 are greater
than the widths W1 and W2 of the linear members 61, 62 of the outer
shaping member 6 (W1<W3 and W2<W4), the linear members 71, 72
constituting the opening defining section 70--which are located on
the leeward side of the vacuum air flowing from outside the drum
toward the inside thereof--will be wider than the linear members
61, 62 constituting the opening defining section 60--which are
located on the windward side--and thus, the vacuum air is less
prone to enter the gaps between the bottom surface 2A of the
collecting/stacking recess 2 and the opening defining section 60
(the linear members 61, 62). Thus, uniform stacking of
shaped-product materials inside the collecting/stacking recess 2 is
promoted, and faulty fiber-stack transferring and loss of shape are
prevented effectively. From the viewpoint of further enhancing the
effect of preventing the intrusion of vacuum air into the gaps
between the bottom surface 2A and the opening defining section 60,
it is preferable that the ratio (W1/W3) between the width W1 of the
width-wise linear member 61 of the opening defining section 60 and
the width W3 of the corresponding width-wise linear member 71 of
the opening defining section 70 is from 0.1 to 1 and more
preferably from 0.2 to 0.7. It is also preferable to set the ratio
(W2/W4) between the width W2 of the circumference-wise linear
member 62 of the opening defining section 60 and the width W4 of
the corresponding circumference-wise linear member 72 of the
opening defining section 70 within the aforementioned range.
[0057] Further, in the present embodiment, because the porous
member 4 is sandwiched between the outer shaping member 6 and the
inner shaping member 7, it is easier to remove the porous member 4
from the rotating drum 1 compared to cases where the porous member
4 is not sandwiched between the shaping members 6, 7, and
replacement can be performed easily in cases where, for example,
the porous member 1 gets clogged with shaped-product materials.
[0058] The aforementioned inner shaping member 7, the porous member
4, the outer shaping member 6, and the ring members 5 are removably
fixed, in this order, to the outer peripheral part of the drum body
3 with, for example, bolts which are not illustrated. In the
present embodiment, each of these members to be fixed to the drum
body 3 has a length. in the longer direction (the drum's
circumferential direction), that substantially half the perimeter
or the rotating drum 1, as illustrated in FIG. 3; thus, the
rotating drum can be assembled by fixing two of each member to the
drum body 3.
[0059] In the present embodiment, as illustrated in FIG. 5, the
outer shaping member 6 is fixed to the inner shaping member 7 by
means of: a plurality of bolt holes (not illustrated) made in the
opening defining section 60 in the recess-bottom-surface
corresponding section 6A; and bolts 8 inserted in the respective
bolt holes. More specifically, as illustrated in FIG. 5, in the
recess-bottom-surface corresponding section 7A of the inner shaping
member 7 overlapping the recess-bottom-surface corresponding
section 6A of the outer shaping member 6 in a planar view of the
collecting/stacking recess 2, bolt holes (not illustrated) are made
in some of the intersection points between the width-wise linear
members 71 and the circumference-wise linear members 72, which
constitute the opening defining section 70, so as to penetrate the
opening defining section 70 and the porous member 4 in the
thickness direction and reach the inside of the opening defining
section 60 of the outer shaping member 6 (i.e., the intersection
points between the width-wise linear members 61 and the
circumference-wise linear members 62, which constitute the opening
defining section 60). The outer shaping member 6, the porous member
4, and the inner shaping member 7 are integrated together by means
of a plurality of bolts 8 inserted into the respective bolt holes
from the surface opposite from the bottom surface 2A of the
collecting/stacking recess 2. The bolt holes reach the inside of
the opening defining section 60, but do not penetrate the opening
defining section 60 in the thickness direction, and thus, the bolts
8 do not protrude from the upper surface of the opening defining
section 60 (the surface opposite from the surface opposing the
porous member 4). By fixing the recess-bottom-surface corresponding
section 6A of the outer shaping member 6 to the
recess-bottom-surface corresponding section 7A of the inner shaping
member 7 by means of bolts as described above, the contact between
the opening defining sections 60, 70 and the porous member 4 is
made tighter and gaps are less likely to be formed therebetween,
and thus, the aforementioned effect can be achieved more
reliably.
[0060] Further, in the present embodiment, the air-impermeable ribs
33 of the drum body 3 (cf. FIG. 3) overlap the opening defining
sections 60, 70 (the linear members 61, 62, 71, 72) of the outer
shaping member 6 and the inner shaping member 7. More specifically,
the outer shaping member 6 is fixed to the drum body 3 such that
some of the width-wise linear members 61 of the opening defining
section 60 that extend in the drum's width direction X overlap the
ribs 33 that, in a planar view, are each in a straight line
extending in the drum's width direction X. Further, the inner
shaping member 7 is also fixed to the drum body 3 such that some of
the width-wise linear members 71 of the opening defining section 70
that extend in the drum's width direction X overlap the ribs 33.
Because the air-impermeable ribs 33 in the recess-bottom-surface
corresponding section 31 of the drum body 3 overlap the linear
members 61 (which are a sparingly air-permeable or air-impermeable
material) constituting the recess-bottom-surface corresponding
section 6A of the outer shaping member 6 and the linear members 71
(which are a sparingly air-permeable or air-impermeable material)
constituting the recess-bottom-surface corresponding section 7A of
the inner shaping member 7, the of effects brought about by the
ribs 33 (i.e., improvement of the strength of the drum body 3 and
the bottom section of the collecting/stacking recess 2, and
prevention of deformation of the bottom section) can be achieved
more reliably while eliminating the problem caused by providing the
ribs 33 (i.e., reduction in the force for sucking the
shaped-product materials by the vacuum air generated from inside
the drum).
[0061] In the fiber stacking device 10, a rotation plate is
circular in planar view and that rotates by receiving power from a
prime mover, such as a motor, is fixed to one end of the rotating
drum 1 in the drum's width direction X (the rotation axis direction
of the rotating drum 1); the drum body 3, the inner shaping member
7, the porous member 4, the outer shaping member 6, and the ring
members 5 rotate integrally about a horizontal axis by the rotation
of the rotation plate. On the other hand, a fixed plate that is
circular in planar view and that is fixed to other constituent
members of the fiber stacking device 10--and thus does not
rotate--is fixed to the other end, in the drum's width direction X,
of the rotating drum 1. The fixed plate has plates fixed thereto
that partition the inside of the rotating drum 1 (the drum body 3)
into a plurality or regions in the circumferential direction, and
these plates form spaces A, B, and C, which are partitioned from
one another, inside the rotating drum 1 (the drum body 3), as
illustrated in FIG. 1. In other words, the spaces A to C are
partitioned from one another by the plates which are provided from
the fixed plate toward the rotation plate. Even when the drum body
3 and the other members fixed to the rotation plate rotate, the
plates fixed to the fixed plate do not rotate; thus, the positions
of the spaces A, B, and C do not change and are fixed. A known
exhaust device (suction means) such as an air-suction fan, which is
not illustrated, is connected to the space A; by operating the
exhaust device, the inside of the space A can be maintained at
negative pressure. While the collecting/stacking recess 2 passes
over the space A, which is maintained at negative pressure, the
fine air-permeation holes in the porous member 4, which forms the
bottom surface 2A of the collecting/stacking recess 2, function as
suction holes.
[0062] The fiber stacking device 10 will further be described. As
illustrated in FIG. 1, the side on one end of the duct 11 covers
the outer peripheral surface of the rotating drum 1 located above
the space A; and the side of the other end of the duct 11, which is
not illustrated, is provided with a shaped-product material
introduction device. The shaped-product material introduction
device includes, for example, a pulverizer that pulverizes a wood
pulp sheet into fibrillated pulp, and that sends the fibrillated
pulp (fiber material) into the duct. A water-absorbent polymer
introduction unit for introducing water-absorbent polymer particles
may be provided in midstream of the duct 11.
[0063] The transfer roller 12 has an air-permeable cylindrical
outer peripheral part, and the outer peripheral part rotates about
a horizontal axis by receiving power from a prime mover, such as a
motor. A space D whose inside can be reduced in pressure is formed
in the non-rotating section inside the transfer roller 12 (the
rotation-axis side). A known exhaust device (not illustrated), such
as an air-suction fan, is connected to the space D; by operating
the exhaust device, the inside of the space D can be maintained at
negative pressure. A multitude of suction holes for communication
between the inside and the outside of the roller are formed in the
outer peripheral surface of the transfer roller 12. While passing
over the space D maintained at negative pressure, the suction holes
suck air from outside to the inside, and with this suction force,
the fiber stack (shaped product) in the collecting/stacking recess
2 is transferred smoothly from the rotating drum 1 onto the
transfer roller 12.
[0064] The vacuum box 13 has a box-like shape having upper and
lower surfaces, left and right side surfaces, and a rear surface,
and has an opening that opens toward the direction of the rotating
drum 1. A known exhaust device (not illustrated), such as an
air-suction fan, is connected to the vacuum box 13 via, for
example, an exhaust pipe which is not illustrated; by operating the
exhaust device, the inside of the vacuum box 13 can be maintained
at negative pressure. It should be noted that the vacuum box 13 is
a device for stably transferring the fiber stack in the
collecting/stacking recess 2 without causing the fiber stack to
lose its shape; so, in cases where the obtained fiber stack 95 (cf.
FIG. 7) is relatively less likely to lose its shape, as in the
present embodiment, there is no need to particularly provide the
vacuum box, or there is no need to use it even if it is provided.
The mesh belt 14 is a member made by endlessly connecting a
band-shaped air-permeable belt having meshes, and moves
continuously along a predetermined route by being guided by a
plurality of free rollers 16 and the transfer roller. The mesh belt
14 is driven by the rotation of the transfer roller 12. As
illustrated in FIG. 1, the mesh belt 14 is arranged such that,
after being introduced onto the outer peripheral surface of the
rotating drum 1 in the vicinity of the downstream end 11a of the
duct 11, the mesh belt sequentially passes between the vacuum box
13 and the rotating drum 1 and between the transfer roller 12 and
the rotating drum 1. The mesh belt 14 is in contact with the outer
peripheral surface of the rotating drum 1 while passing the front
of the opening in the vacuum box 13, and the mesh belt is separated
from the outer peripheral surface of the rotating drum 1 and moves
onto the transfer roller 12 in the vicinity of a section where the
transfer roller 12 and the rotating drum 1 come nearest to one
another.
[0065] The mesh belt 14 has fine holes that are smaller than the
suction holes of the transfer roller 12; in association with
suction from the suction holes of the transfer roller 12, suction
is also conducted from the fine holes in the mesh belt 14 that over
the suction holes. The windshield plates 15 are provided, in a
pair, on opposite sides of a width-wise region where the suction
holes are formed in the outer peripheral surface of the transfer
roller 12 so as to sandwich this region. The windshield plates 15
prevent or reduce the inflow of air from the sides, and also
prevent the fiber stack (shaped product), which has been released
from the collecting/stacking recess 2, from losing its shape.
[0066] The following describes a method for continuously
manufacturing absorbent cores by using the aforementioned fiber
stacking device 10--i.e., an embodiment of the absorbent core
manufacturing method of the present invention. The manufacturing
method of the present embodiment involves a fiber stacking step of
sucking and stacking, in the collecting/stacking recess 2 of the
rotating drum 1, an absorbent-core material (shaped-product
material) supplied on an air stream.
[0067] Before executing the fiber stacking step, the space A inside
the rotating drum 1, the space D inside the transfer roller 12, and
the inside of the vacuum box 13 are reduced to negative pressures
by actuating the respective exhaust devices connected thereto. By
reducing the inside of the space A to negative pressure, an air
stream (vacuum air) for transporting the absorbent-core material
onto the outer peripheral surface of the rotating drum 1 is
generated inside the duct 11. Also, the rotating drum 1 and the
transfer roller 12 are rotated, and the not-illustrated vacuum
conveyor arranged below the transfer roller 12 is actuated.
[0068] When the fiber material introduction device is actuated and
the absorbent-core material is supplied into the duct 11, the
absorbent-core material floats on the air stream flowing in the
duct 11 and is supplied, in a dispersed airborne state, toward the
outer peripheral surface of the rotating drum 1.
[0069] While the collecting/stacking recess 2 of the rotating drum
1 is being transported along the section covered by the duct 11,
the absorbent-core material 94 is sucked and stacked in the
collecting/stacking recess 2, as illustrated in FIG. 6. In the
preset embodiment, as illustrated in FIG. 6, the absorbent-core
material 94 is stacked not only in the openings 65 of the
recess-bottom-surface corresponding section 6A of the outer shaping
member 6, where suction from the bottom surface 2A is conducted,
but also on the opening defining section 60 (the linear members 61,
62) where suction from the bottom surface 24 is act conducted. On
the upstream side of the duct 11, the absorbent-core material is
stacked only in the openings 65, but after the height of the
stacked absorbent-core material reaches the thickness of the
opening defining section 60 (the linear members 61, 62), the
absorbent-core material starts getting stacked also on the opening
defining section 60 (the linear members 61, 62) in accordance with
the intertwining among pieces of the absorbent-core material and
the flow of air inside the duct 11 transporting the absorbent-core
material. On the downstream side of the duct 11. the
collecting/stacking recess 2 is completely covered with the
absorbent-core material.
[0070] After the absorbent-core material 94 is stacked in the
collecting/stacking recess 2 and a fiber stack 95 is obtained, the
rotating drum 1 is further rotated. When the fiber stack 95 in the
collecting/stacking recess 2 reaches a position in opposition to
the vacuum box 13 the fiber stack 95 is sucked onto the mesh belt
14 by suction from the vacuum box 13, and is transported, in this
state, to a section where the transfer roller 12 and the rotating
drum 1 crane nearest to one another, or to the vicinity thereof.
Then, the fiber stack 95, which is sucked on the mesh belt 14, is
released from the collecting/stacking, recess 2 by suction from the
transfer roller 12 side, and is transferred onto the transfer
roller 12 together with the mesh belt 14. By the effects brought
about by the specific features of the rotating drum 1 as described
above, releasing of the fiber stack 95 from the collecting/stacking
recess 2 and transferring of the fiber stack 95 onto the transfer
roller 12 occur smoothly without any problems.
[0071] FIG. 7 illustrates a portion of a fiber stack 95 immediately
alter being released from the collecting/stacking recess 2. As
illustrated in FIG. 7, in the fiber stack 95, sections
corresponding to the openings 65 of the recess-bottom-surface
corresponding section 6A of the outer shaping member 6 constitute
thick sections (high basis-weight sections) 95A in which the amount
of absorbent-core material stacked is relatively large, and
sections corresponding to the opening defining section 60 (the
linear members 61, 62) of the recess-bottom-surface corresponding
section 6A constitute thin sections (low basis-weight sections) 95B
in which the amount of absorbent-core material stacked is
relatively small. Further, one surface 95a of the fiber stack 95 is
substantially flat, while the other surface 95b has a
projecting-and-recessed surface with large undulations. The
projecting-and-recessed surface 95b has a plurality of recesses
(grooves; thin sections 95B) that, in planar view, are in
continuous straight lines extending in the drum's width direction X
and the direction orthogonal thereto (the direction corresponding
to the drums circumferential direction), the recesses being
arranged in a lattice pattern. The protrusions (thick sections 95A)
that have a rectangular shape in planar view are arranged an the
respective cells of the lattice.
[0072] The fiber stack 95 transferred onto the transfer roller 12
is transported while being sucked from the transfer roller 12 side,
and is then passed on to a core-wrap sheet 96 that is made, for
example, of tissue paper or a liquid-permeable nonwoven fabric and
that has been introduced onto the not-illustrated vacuum conveyor
arranged below the transfer roller 12. Then, both side sections of
the core-wrap sheet 96 that extend along the transporting direction
are folded back, and both the upper and lower surfaces of the fiber
stack 95 are covered with the core-wrap sheet 96. Then, if
necessary, the fiber stack 95, which is now covered with the
core-wrap sheet 96, is compressed in the thickness direction by a
compression means (not illustrated) such as a press roller, and is
then cut into a predetermined size with a cutter, to thereby obtain
an absorbent core which consists of the shaped product covered with
the core-wrap sheet 96. It should be noted that in cases where the
fiber stack 95 is compressed in the thickness direction, the thick
sections (high basis-weight sections) 95A constitute high density
sections having a relatively high density, and the thin sections
(low basis-weight sections) 95B constitute low density sections
having at relatively low density.
[0073] The absorbent core of the present invention is suitable as a
constituent member of an absorbent article, such as a disposable
diaper or a sanitary napkin. An example of an absorbent article
employing the absorbent core of the present invention is an article
including the aforementioned absorbent core and a sheet material to
which the absorbent core is fixed. The sheet material may be
arranged only on the side of one surface (the skin-opposing surface
or the skin-non-facing surface) of the absorbent core, or may be
arranged on both surfaces of the absorbent core. In the latter
case, a liquid-permeable topsheet may be used as the sheet material
arranged on the skin-facing surface side of the absorbent core, and
a liquid-impermeable or water-repellent backsheet may be used as
the sheet material arranged on the skin-non-facing surface side of
the absorbent core. It should be noted that the skin-facing surface
is the surface of the absorbent article, or a constituent member
thereof (e.g. the absorbent core), that faces toward the side of
the wearer's skin when the absorbent article is worn; the
skin-non-facing surface is the surface of the absorbent article, or
a constituent member thereof, that faces the opposite side (the
clothing side) from the skin side when the absorbent article is
worn.
[0074] A method for manufacturing an absorbent article including
the absorbent core of the present invention and a sheet material to
which the absorbent core is fixed involves a step of fixing, onto
the sheet material (e.g., topsheet, backsheet, etc.), the absorbent
core obtained by executing the aforementioned manufacturing method.
The "fixing of the absorbent core to the sheet material" may be
perforated by known fixing means, such as a hot-melt adhesive,
thermal fusion bonding, or the like. Further, the "fixing of the
absorbent core to the sheet material" encompasses sandwiching the
absorbent core between at least two sheet materials, without
directly joining the absorbent core to the sheet material(s).
[0075] The following describes other embodiments of the present
invention. The following description on the other embodiments will
focus mainly on constituent parts that are different from the
foregoing embodiment, and similar constituent parts will be
accompanied by the same reference symbols and explanation thereof
will be omitted. The explanation given for the foregoing embodiment
applies as appropriate to constituent parts that are not
particularly explained below.
[0076] FIGS. 8 and 9 illustrate another embodiment of the rotating
drum according to the present invention. The porous member 4A in
the rotating drum of this other embodiment includes an
air-impermeable section 45 in a section 40 corresponding to the
opening defining section 60 (linear members 61, 62) of the outer
shaping member 6 and/or the opening defining section 70 (linear
members 71, 72) of the inner shaping member 7 (i.e., the section
overlapping the opening defining section 60 and/or the opening
defining section 70 in a planar view of the collecting/stacking
recess 2; referred to hereinafter also as "opening-defining-section
corresponding section 40"). More specifically, as regards the outer
shaping member 6 and the inner shaping member 7 which are arranged
so as to oppose one another across the porous member 4A, the
plurality of openings 65 in the outer shaping member 6 are in
one-to-one correspondence with the plurality of openings 75 in the
inner shaping member 7. as described above; thus, the
opening-defining-section corresponding section 40 of the porous
member 4A is the section sandwiched between the opening defining
section 60 (linear members 61, 62) of the outer shaping member 6
and the opening defining section 70 (linear members 71, 72) of the
inner shaping member 7, as illustrated in FIG. 8, and this section
constitutes the air-impermeable section 45.
[0077] The air-impermeable section 45 does not have air-permeation
holes (holes that penetrate the porous member 4A in the thickness
direction) which are formed in other sections the porous member 4A,
and is thus air-impermeable. Here, "air impermeability" of the
air-impermeable section 45 has the same meaning as the air
impermeability of the opening defining sections 60, 70 described
above, and means that there is substantially no air permeability.
Thus, the air-impermeable section 45 substantially does not allow
the passage of vacuum air which flows from the outside of the drum
toward the inside thereof at the time of stacking the
shaped-product material, and thus functions as a non-suction
section where suction from the bottom surface 2A of the
collecting/stacking recess 2 is not performed.
[0078] FIG. 9 illustrates concrete examples of the air-impermeable
section 45. In the embodiment illustrated in FIG. 9(a), the entire
area of the opening-defining-section corresponding section 40 of
the porous member 4A constitutes the air-impermeable section 45,
and sections, in the porous member 44, other than the
opening-defining-section corresponding section 40 have
air-permeation holes and do not constitute air-impermeable
sections. In other words, in the embodiment illustrated in FIG.
9(a), the air-impermeable section 45 consists of: a plurality of
width-wise air-impermeable sections 45A that, in planar view, are
in continuous straight lines and that are in one-to-one
correspondence with the plurality of width-wise linear members 61
constituting the opening defining section 60 and the plurality of
width-wise linear members 71 constituting the opening defining
section 70; and a plurality of circumference-wise air-impermeable
sections 458 that, in planar view, are in continuous straight lines
and that are in one-to-one correspondence with the plurality of
circumference-wise linear members 62 (four in this embodiment)
constituting the opening defining section 60 and the plurality of
circumference-wise linear members 72 (four in this embodiment)
constituting the opening defining section 70. The opening defining
sections 60, 70 and the air-impermeable section 45 have the same
shape in a planar view of the collecting/stacking recess 2, and all
have a lattice shape in planar view. From the viewpoint of
fiber-stack releasability, the width of the width-wise
air-impermeable section 45A of the opening-defining-section
corresponding section 40 is preferably the some or greater than the
width of the width-wise linear member 61 and width-wise linear
member 71. From the same viewpoint, the width of the
circumference-wise air-impermeable section 45B of the
opening-defining-section corresponding section 40 is preferably the
same or greater than the width of the circumference-wise linear
member 62 and circumference-wise linear member 72.
[0079] The air-impermeable section 45 (45A, 45B) illustrated in
FIG. 9(a) can be formed by joining a separate air-impermeable
member--such as an air-impermeable member made of e.g. metal,
resin, or silicone--to a section where the multitude of fine holes
(air-permeation holes) are formed in the porous member 4A.
Alternatively, the air-impermeable section 45 (45A, 45B)
illustrated in FIG. 9(a) may be formed of a section in which
air-permeation holes are not formed in the porous member.
Specifically, for example, in cases of using, as the porous member
4A, a member in which a multitude of fine holes are formed by
etching or punching in an air-impermeable plate made of metal or
resin, the air-impermeable section 45 (45A, 45B) illustrated in
FIG. 9(a) can be formed by intentionally not forming the fine holes
in a predetermined section of the plate.
[0080] Alternatively, the air-impermeable section 45 may be formed
by joining the porous member 4A (the opening-defining-section
corresponding section 40) with the shaping members 6, 7 (the
opening defining sections 60, 70 (the linear members 61, 62, 71,
72)). Examples of this joining method include: welding
(melt-uniting) in which sections to be joined in the porous member
4A and the shaping members 6, 7 are molten by heat, and the molten
sections are directly fused together, and a method in which the
porous member 4A is joined with the shaping members 6, 7 by means
of an adhesive. The air-permeation holes initially formed in the
porous member 4A are closed by welding or with the adhesive, and
thus, the section joined to the shaping members 6, 7 by welding or
with the adhesive becomes the air-impermeable section 45.
[0081] FIG. 9(b) illustrates an example of air-impermeable sections
45 consisting of sections where the porous member 4A is joined to
the shaping members 6, 7 by welding or with an adhesive. In the
embodiment illustrated in FIG. 9(b), a plurality of air-impermeable
sections 45 which are circular in planar a plurality of sections
where the porous member 4A is joined to the shaping members 6, 7 by
welding or with an adhesive--are formed at predetermined intervals
in the opening-defining-section corresponding section 40, which has
a lattice shape in planar view, a the porous member 4A; the
air-impermeable sections 45 are formed non-consecutively in both
the drum's width direction X and the drum's circumferential
direction which is orthogonal thereto. A section corresponding to
the interval between two adjacent air-impermeable sections 45, 45
has air-permeation holes (air-permeation boles initially formed in
the porous member 4A) formed therein, and thus has air
permeability.
[0082] As described above, the entire area of the
opening-defining-section corresponding section 40 of the porous
member 4A (i.e., the section overlapping the opening defining
sections 60, 70 in a planar view of the collecting/stacking recess
2) may constitute the air-impermeable section 45 as illustrated in
FIG. 9(a), or alternatively, only portions (the sections where the
porous member 4A is joined to the shaping members 6, 7 by welding
or with an adhesive) of the opening-defining-section corresponding
section 40 may constitute air-impermeable sections 45 as
illustrated in FIG. 9(b), and the opening-defining-section
corresponding section 40, as a whole, may have "low air
permeability" that is lower than the air permeability of sections,
in the porous member 4A, other than the opening-defining-section
corresponding section 40.
[0083] Even with the other embodiments illustrated in FIGS. 8 and
9, the same effects as those of the foregoing embodiment can be
achieved. Particularly, in the other embodiments illustrated in
FIGS. 8 and 9, one or more air-impermeable sections 45 are formed
in the opening-defining-section corresponding section 40 of the
porous member 4A; thus, problems--e.g., the shaped-product
materials (absorbent-core materials), such as pulp, getting caught
between the porous member 4A and the opening defining section 60 of
the outer shaping member 6--are even less likely to occur, and
uniform stacking of shaped-product materials inside the
collecting/stacking recess 2 is further promoted because the vacuum
air for carrying the shaped-product materials is rectified more
easily. Thus, shaped products (absorbent cores) with good shape and
without shape loss can be manufactured efficiently.
[0084] FIGS. 10 to 13 illustrate main parts of rotating drums 1A,
1B and 1C according to further embodiments of the rotating drum of
the present invention. Each of the rotating drums 1A, 1B, and 1C is
constructed similarly to the foregoing embodiment, except that the
shapes of the outer shaping member, the inner shaping member, and
the ring members are different. Absorbent cores (shaped products)
obtained by using the rotating drum 1A (cf. FIGS. 10 and 11) and
absorbent cores (shaped products) obtained by using the rotating
drum 1B (cf. FIG. 12) are particularly suitable as absorbent cores
for disposable diapers, and absorbent cores (shaped products)
obtained by using the rotating drum 1C are particularly suitable as
absorbent cores for sanitary napkins. It should be noted that FIGS.
10 to 13 illustrate only a portion, in the circumferential
direction, of the rotating drum (FIGS. 10 to 12 illustrate a
portion amounting to one unit of an absorbent core, and FIG. 13
illustrates a portion amounting to two units of absorbent cores),
and each of the rotating drums 1A, 1B, and 1C is constructed by
continuously arranging, in the drum's circumferential direction, a
plurality of the aforementioned portions amounting to one or two
units of absorbent cores as illustrated in these figures.
[0085] As illustrated in FIGS. 10 and 11, in the outer shaping
member 6P and the inner shaping member 7P of the rotating drum 1A,
the entire shaping members each constitute a recess-bottom-surface
corresponding section overlapping the bottom surface 2A (of FIG. 4)
of the collecting/stacking recess 2 in a planar view thereof. As
illustrated in FIG. 11, the outer shaping member 6P is constituted
by: a plurality of openings 65A, 65B that penetrate the outer
shaping member 6P (recess-bottom-surface corresponding section) in
the thickness direction; and an opening defining section 60 that
partitions and forms the openings 65A, 65B. The opening defining
section 60 of the outer shaping member 6P consists of: lattice
sections 63, 63 that are located at the respective ends, in the
drum's circumferential direction, of a portion of the opening
defining section 60 amounting to a single absorbent-core unit, and
that are each formed in a lattice pattern, in planar view, by a
plurality of intersecting linear members which are each in a
straight line in planar view; and a pair of non-straight-line
linear members 64, 64 that are sandwiched between the lattice
sections 63, 63 and that extend in the drum's circumferential
direction. The openings 65A are located at the respective lattice
cells of each lattice section 63, and each have a square shape in
planar view, wherein the diagonal line (not illustrated) of each
square shape coincides with the drum's circumferential direction.
The opening defining section 60 also includes linear members that
look like an extension of the lattice sections 63, 63 in the
opposite direction from the opening 65B, and that do not form
openings surrounded by the linear members. The opening 65B is
located between the pair of linear members 64, 64, and is
continuous across the entire length between the lattice sections
63, 63. Each of the linear members 64, 64 is curved such that the
central section thereof in the drum's circumferential direction is
located more inward, in the drum's width direction X, than the end
sections of each linear member 64. As illustrated in FIG. 10,
openings in which the shaped-product materials (absorbent-core
materials) can be stacked are formed between the outer shaping
member 6P and a pair of ring members 51, 51 surrounding it. The
opening 65B is located between the pair of linear members 64, 64,
and is continuous across the entire length between the lattice
sections 63, 63. Each or the linear members 64, 64 is curved such
that the central section thereof in the drum's circumferential
direction is located more inward, in the drum's width direction X,
than the end sections thereof.
[0086] The inner shaping member 7P of the rotating drum 1A has the
same shape as the outer shaping member 6P, and the dimensions of
the parts/members are also the same. As illustrated in FIG. 11, the
inner shaping member 7P is constituted by; a plurality of openings
75A, 75B that penetrate the inner shaping member 7P
(recess-bottom-surface corresponding section) in the thickness
direction; and an opening defining section 70 that partitions and
forms the openings 75A, 75B.The opening defining section 70
consists of a pair of non-straight-line linear members 74, 74 that
extend in the drum's circumferential direction and that are
sandwiched between lattice sections 73, 73 each formed in a lattice
pattern, in planar view, by a plurality of intersecting linear
members which are each in a straight line in planar view. The
opening defining section 70 (the lattice sections 73 and the linear
members 74) of the inner shaping member 7P is in one-to-one
correspondence with the opening defining section 60 (the lattice
sections 63 and the linear members 64) of the outer shaping member
6P.
[0087] As illustrated in FIGS. 10 and 11, in each ring member 51 of
the rotating drum 1A, the inner edge 51a extending in the drum's
circumferential direction includes a curved line, and has a curved
section that protrudes inward in the drum's width direction X. The
curved section of the inner edge 51a of each ring member 51 is
located on the outside in the drum's width direction X, of each of
the linear members 64, 64. The inner edges 51a of the respective
ring members 51 are sections that determine the planar-view shape
of the length-wise, side edges (in the drum's circumferential
direction) of the absorbent core (shaped product) formed in the
collecting/stacking recess 2.
[0088] The rotating dram 1B illustrated in FIG. 12 is constructed
similarly to the rotating drum 1A, except for the outer shaping
member 6Q and the inner shaping member 7Q. The outer shaping member
6Q of the rotating drum 1B is constituted by: a plurality openings
65 that penetrate the outer shaping member 6Q
(recess-bottom-surface corresponding section) in the thickness
direction; and an opening defining section 60 that partitions and
forms the openings 65. The entire opening defining section 60 of
the outer shaping member 6Q is formed in a lattice pattern, in
planar view, by a plurality of intersecting linear members 61, 62
which are each in a straight line in planar view, and the opening
defining section 60 includes wide sections 66 whose length in the
drum's width direction X is relatively long, and a narrow section
67 whose length is relatively short. The wide sections 66 are
located at the respective ends, in the drum's circumferential
direction, of a portion of the opening defining section 60
amounting to a single absorbent-core unit. The narrow section 67 is
sandwiched between the wide sections 66, 66.
[0089] The inner shaping member 7Q of the rotating drum 1B has the
same shape as the outer shaping member 6Q, and the dimensions of
the parts/members are also the same. As illustrated in FIG. 12, the
inner shaping member 7Q is constituted by: a plurality of openings
75 that penetrate the inner shaping member 7Q
(recess-bottom-surface corresponding section) in the thickness
direction; and an opening defining section 70 that partitions and
forms the openings 75. The entire opening defining section 70 is
formed in a lattice pattern, in planar view, by a plurality of
intersecting linear members 71, 72 which are each in a straight
line in planar view, and the opening defining section includes wide
sections 76 whose length in the drum's width direction X is
relatively long, and a narrow section 77 whose length is relatively
short. The wide sections 76 are located at the respective ends, in
the drum's circumferential direction, of a portion of the opening
defining section 70 amounting to a single absorbent-core unit. The
narrow section 77 is sandwiched between the wide sections 76, 76.
The opening defining section 70 (the wide sections 76 and the
narrow section 77) of the inner shaping member 7Q is in one-to-one
correspondence with the opening defining section 60 (the wide
sections 66 and the narrow section 67) of the outer shaping member
6Q.
[0090] The rotating drum 1C illustrated in FIG. 13 is constructed
similarly in the rotating drum 1 illustrated in FIG. 3, except for
the ring member 52, the outer shaping member 6R, and the inner
shaping member 7R. The ring member 52 of the rotating drum 1C has,
in the central section thereof in the drum's width direction X, a
plurality of (two) windows 53 thrilled at predetermined intervals
in the drum's circumferential direction, each window 53 being oval
in planar view and corresponding to a single unit or an absorbent
core. The space between the two adjacent windows 53, 53 constitutes
a non-fiber-stacking section where no absorbent-core material
(shaped-product material) is stacked.
[0091] The outer shaping member 6R or the rotating drum 1C is
constructed similarly to the outer shaping member 6 of the rotating
drum 1 illustrated in FIG. 3, except for the pattern according to
which the openings 65 (linear members 61, 62) are arranged. As
illustrated in FIG. 13, the plurality of openings 65 in the outer
shaping member 6R (recess-bottom-surface corresponding section 6A)
are arranged in a staggered pattern. Here, a "staggered pattern" is
an arrangement wherein: a plurality of rows, each including a
plural it of openings 65 arranged at regular intervals in the
drum's circumferential direction, are arranged in the drum's width
direction X, which is orthogonal to the drum's circumferential
direction; and, in the drum's width direction X, the openings 65
are misaligned (preferably, misaligned by half a pitch) from one
another between two adjacent rows. It should be noted that
"arranged in a staggered pattern" in the present invention not only
encompasses an embodiment in which the openings 65 are arranged
perfectly according to the aforementioned explanation, but also
encompasses cases where slight unintentional misalignments in
arrangement, such as inevitable misalignments during manufacture,
have occurred.
[0092] The inner shaping member 7R of the rotating drum 1C has the
same shape as the outer shaping member 6R, and the dimensions of
the parts/members are also the same. As illustrated in FIG. 13, the
inner shaping member 7R is constituted by: a plurality of openings
75 that penetrate the recess-bottom-surface corresponding section
7A of the inner shaping member 7R in the thickness direction; and
an opening defining section 70 that partitions and forms the
openings 75. The openings 75 are arranged in a staggered pattern,
and the opening defining section 70 is constituted by including a
plurality of intersecting linear members 71, 72 which are each in a
straight line in planar view. The opening defining section 70 (the
linear members 71, 72) of the inner shaping member 7R is in
one-to-one correspondence with the opening defining section 60 (the
linear members 61, 62) of the outer shaping member 6R.
[0093] The present invention is not limited to the foregoing
embodiments and can be modified as appropriate. For example, in the
foregoing embodiment, the collecting/stacking recess 2 was formed
continuously in the outer peripheral surface of the rotating drum 1
along the entire length in the circumferential direction, but the
recess may be formed intermittently in the circumferential
direction. In this case, the outermost surface between two
collecting/stacking recesses 2, 2 adjacent to one another in the
circumferential direction may be formed of an air-impermeable ring
member 5, so that shaped-product materials will not get stacked
between the recesses 2, 2. Further, in the foregoing embodiment.
the members 7, 4, 6, and 5 fixed to the drum body 3 each had a
length that is substantially half the perimeter of the rotating
drum 1, and two of each member were combined to form the drum.
However, each of the members may be made of a single annular
member, or alternatively, three or more of each member may be
combined. Moreover, the ring members 5 do not have to be arranged
outside the outer shaping member 6. Further, the term "linear" in
the linear members 61, 62, 64, 71, 72, 74 constituting the opening
defining sections 60, 70 is not limited to a straight line in a
planar view of the collecting/stacking recess 2, as described in
the foregoing embodiments, but encompasses curved lines and beat
lines.
[0094] Further, in the foregoing embodiment, the outer shaping
member 6 and the inner shaping member 7 had a single layer
structure. However, they may have a multi-layer structure in which
a plurality of relatively thin shaping members are laminated. By
providing the outer shaping member 6 and the inner shaping member 7
with multi-layer structures, it becomes possible to process the
shaping members easily and manufacture shaped products with various
shapes, compared to cases where the shaping members have a single
layer structure.
[0095] Further, in the foregoing embodiment, the bolts 3 for fixing
the outer shaping member 6 to the inner shaping member 7 were
inserted from the side of the inner shaping member 7 toward the
side of the outer shaping member 6 (i.e., from the inside of the
drum toward the outside). However, the bolts may be inserted
oppositely from the outer shaping member 6 side toward the inner
shaping member 7 side (i.e., from the outside of the drum toward
the inside).
[0096] Further, the foregoing embodiment, the openings 65 were in
one-to-one correspondence with the openings 75, and the planar-view
shapes of corresponding openings 65, 75 were congruent; thus, the
opening defining section 60 of the outer shaping member 6 and the
opening defining section 70 of the inner shaping member 7 were
congruent in terms of planar-view shape and thus entirely
overlapped one another in a planar view of the collecting stacking
recess 2. However, the planar-view shapes of the opening defining
sections 60, 70 do not have to be the same, and only a portion
thereof may overlap one another in a planar view of the
collecting/stacking recess 2. For example, the opening defining
section 70 of the inner shaping member 7 may be formed in a lattice
pattern in planar view as illustrated in FIG. 3, and the opening
defining section 60 of the outer shaping member 6 may be
constituted only by a plurality of width-wise air-impermeable
members that, in planar view. are in straight lines extending in
the drum's width direction X, and thus formed in a ladder pattern
in planar view.
[0097] Further, in the foregoing embodiment, the ring members 5
were attached to the outer peripheral surface of the rotating drum
1. However, the ring members do not have to be used, and
protrusions may be formed on the side sections of the outer shaping
member 6, and the protrusions may be employed as members achieving
the same effect as the ring members. Further, in the foregoing
embodiment, the length of each ring member 5 in the drum's width
direction was constant, but the length of each ring member 5 in the
drum's width direction may be changed along the drum's
circumferential direction by, for example, changing the shape of
the inner edge or each ring member 5 (i.e., the side edge on the
inner end surface side) along the drum's circumferential direction.
In this way, the width and shape of the shaped product can be
changed along the drum's circumferential direction. Parts/members
in any one of the foregoing embodiments can all be mutually
employed, as appropriate, in other embodiments.
[0098] In relation to the for going embodiments of the present
invention, the following additional features for the fiber stacking
device, the absorbent core manufacturing method, and the absorbent
article manufacturing method) are disclosed.
<1> A fiber stacking device comprising a rotating drum that
has a collecting/stacking recess in an outer peripheral surface
thereof, wherein the rotating drum forms a shaped product by
stacking a shaped-product material by sucking the material with a
bottom surface of the collecting/stacking recess, wherein:
[0099] the rotating drum includes a drum body, and an air-permeable
porous member that forms the bottom surface of the
collecting/stacking recess;
[0100] the porous member is sandwiched between an outer shaping
member arranged so as to oppose the bottom surface of the
collecting/stacking recess, and an inner shaping member arranged
between the porous member and the drum body; both the shaping
members are arranged so as to overlap the porous member;
[0101] each of the shaping members has a recess-bottom-surface
corresponding section that overlaps the bottom surface of the
collecting/stacking recess in a planar view of the
collecting/stacking recess; each the recess-bottom-surface
corresponding section is constituted by a plurality of openings
that penetrate the recess-bottom-surface corresponding section in
the thickness direction, and an opening defining section that
partitions and forms the openings; and the opening defining section
of the inner shaping member corresponds to the opening defining
section of the outer shaping member.
<2> The fiber stacking device according to the aforementioned
item <1>, wherein the opening defining section of the
respective shaping members is air-impermeable. <3> The fiber
stacking device according to the aforementioned item <1> or
<2>, wherein the porous member includes an air-impermeable
section in a section corresponding to the opening defining section
of the cuter shaping member and or the inner shaping member.
<4> The fiber stacking device according to the aforementioned
item <3>, wherein the air-impermeable section is formed by
joining the porous member with the outer shaping member and the
inner shaping member. <5> The fiber stacking device according
to the aforementioned item <3> or <4>, wherein the air
-impermeable section is formed by: (1) a welding (melt-uniting)
method in which sections to be joined in the porous member, the
outer shaping member, and the inner shaping member are molten by
heat, and the molten sections are directly fused together; or (2) a
method in which the porous member is joined with the outer shaping
member and the inner shaping member by means of an adhesive.
<6> The fiber stacking device according to any one of the
aforementioned items <3> to <5>, wherein either: the
entire area of an opening-defining-section corresponding section (a
section overlapping the opening defining section of the outer
shaping member and the opening defining section or the inner
shaping member in a planar view of the collecting/stacking recess)
of the porous member constitutes the air-impermeable section; or
only a portion (a section where the porous member and both the
shaping members are joined by welding or with an adhesive) of the
opening-defining-section corresponding section constitutes the
air-impermeable section, and the opening-defining-section
corresponding section, as a whole, has low air permeability that is
lower than the air permeability of sections, in the porous member,
other than the opening-defining-section corresponding section.
<7> The fiber stacking device according to any one of the
aforementioned items <1> to <6>, wherein the plurality
of the openings disposed in the outer shaping member are in
one-to-one correspondence with the plurality of the openings
disposed in the inner shaping member, <8> The fiber stacking
device according to the aforementioned item <7>, wherein, in
a planar view of the collecting/stacking recess, the openings in
the outer shaping member and the openings in the inner shaping
member overlap one another. <9> The fiber stacking device
according to the aforementioned item <7> or <8>,
wherein, in a planar view of the collecting/stacking, recess,
wherein, in a planar view of the collecting/stacking recess, the
opening disposed in the outer shaping member and the opening
disposed in the inner shaping member that overlap one another are
congruent or similar to one another in terms of planar-view shape.
<10> The fiber stacking device according to any one of the
aforementioned items <1> to <9>, wherein the opening
defining section of the respective shaping members is constituted
by linear members extending along the bottom surface of the
collecting/stacking recess. <11> The fiber stacking device
according to the aforementioned item <10>, wherein: the
opening defining section of each of the outer shaping member and
the inner shaping member includes, as the aforementioned linear
members, a plurality of width-wise linear members that, in a planar
view, are each in a straight line extending in the width direction
of the drum, and a plurality of circumference-wise linear members
that, in a planar view, are each in a straight line orthogonal to
the plurality of width-wise linear members, and each opening
defining section is formed in a lattice pattern, in planar view, by
the linear members; and the openings in each shaping member are
located at the respective cells of the lattice, and each have a
rectangular shape in a planar view. <12> The fiber stacking
device according to the aforementioned item <10> or
<11>, wherein the width of the linear member (of the opening
defining section) of the outer shaping member is the same as the
width of the linear member (of the opening defining section) of the
inner shaping member located right beneath the aforementioned
linear member across the porous member. <13> The fiber
stacking device according to the aforementioned item <10> or
<11>, wherein the width of the linear member (of the opening
defining section) of the outer shaping member is different from the
width of the linear member (of the opening defining section) of the
inner shaping member that overlaps the linear member of the outer
shaping member in a planar view of the collecting/stacking recess.
<14> The fiber stacking device according to the
aforementioned item <13>, wherein the width of the linear
member (of the opening defining section) of the inner shaping
member is greater than the width of the linear member (of the
opening defining section) of the outer shaping member. <15>
The fiber stacking device according to any one of the
aforementioned items <10> to <14>, wherein the ratios
(W1/W3 and W2/W4) between the widths W1 and W2 of the linear
members (of the opening defining section) of the outer shaping
member and the respectively corresponding widths W3 and W4 of the
linear members (of the opening defining section) of the inner
shaping member are from 0.1 to 1, or from 0.2 to 0.7. <16>
The fiber stacking device according to any one of the
aforementioned items <10> to <15>, wherein the width of
each linear member constituting the opening defining section of the
outer shaping member is from 1 to 10 mm.
[0102] <17> The fiber stacking device according to any one of
the aforementioned items <1> to <16>, wherein the outer
shaping member is fixed to the inner shaping member by means of: a
plurality of bolt holes made in the opening defining section in the
recess-bottom-surface corresponding section; and bolts inserted in
the respective bolt holes.
<18> The fiber stacking device according to any one of the
aforementioned items <1> to <17>, wherein;
[0103] the drum body has a recess-bottom-surface corresponding
section that overlaps the bottom surface of the collecting/stacking
recess in a planar view of the collecting/stacking recess; the
recess-bottom-surface corresponding section is constituted by a
plurality of through holes that penetrate the recess-bottom-surface
corresponding section in the thickness direction, and
air-impermeable ribs each located between the two adjacent through
holes; and
[0104] in a planar view of the collecting/stacking recess, the ribs
overlap the opening defining sections of the respective shaping
members.
<19> The fiber stacking device according to any one of the
aforementioned items <1> to <18>, wherein the bottom
surface of the collecting/stacking recess has a flat form.
[0105] <20> The fiber stacking device according to any one of
the aforementioned items <1> to <19>, wherein:
[0106] the drum body is made of a stiff, metal tube, and has, in
the central section in the width direction of the drum, a
recess-bottom-surface corresponding section that overlaps the
bottom surface of the collecting/stacking recess in a planar view
thereof; and
[0107] the recess-bottom-surface corresponding section is
constituted by a plurality of through openings that penetrate the
recess-bottom-surface corresponding section in the thickness
direction, and air-impermeable ribs each located between two
adjacent through openings.
<21> The fiber stacking device according to any one of the
aforementioned items <1> to <20>, wherein: the porous
member is a metal or resin mesh, or a porous metal plate or resin
plate in which a multitude of fine holes are formed in a metal or
resin plate by etching or punching; and air-permeation holes having
a diameter of from 0.2 to 0.6 mm are formed in the porous member at
a pitch of from 0.4 to 1.5 mm. <22> The fiber stacking device
according to any one of the aforementioned items <1> to
<21>, wherein: the rotating drum includes ring members that
form the respective inner-side surfaces of the collecting/stacking
recess; and the ring members are arranged on the respective side
sections, in the width direction, of the outer peripheral surface
of the rotating drum with the collecting/stacking recess sandwiched
therebetween. <23> The fiber stacking device according to any
one of the aforementioned items <1> to <22>, wherein
the opening defining section of the inner shaping member is always
arranged in opposition to the opening defining section of the outer
shaping member, but the inner shaping member has an opening
defining section that does not correspond to the opening defining
section of the outer shaping member. <24> The fiber stacking
device according to any one of the aforementioned items <1>
to <23>, wherein the collecting/stacking recess is either
formed continuously in the outer peripheral surface of the rotating
drum along the entire length in the circumferential direction, or
formed intermittently along the circumferential direction.
<25> The fiber stacking device according to any one of the
aforementioned items <1> to <24>, wherein the fiber
stacking device includes: a duet that supplies the shaped-product
material to the outer peripheral surface of the rotating drum; a
transfer roller that is driven to rotate and that is arranged
obliquely below the rotating drum; and a vacuum conveyor arranged
below the transfer roller. <26> The fiber stacking device
according to the aforementioned item <25>, wherein the fiber
stacking device includes: a vacuum box provided between the duct
and the transfer roller in the circumferential direction of the
rotating drum, and a mesh belt arranged so as to pass between the
vacuum box and the rotating drum and between the is transfer roller
and the rotating drum. <27> A method for manufacturing an
absorbent core by using fiber stacking device according to any one
of the aforementioned items <1> to <24>, the absorbent
core manufacturing method comprising:
[0108] a fiber stacking step of sucking and stacking, in the
collecting/stacking recess of the rotating drum, an absorbent-core
material supplied on an air stream.
<28> A method for manufacturing an absorbent core by using
the fiber stacking device according to the aforementioned item
<25>, the absorbent core manufacturing method including:
[0109] a fiber stacking step of sucking and stacking, in the
collecting/stacking recess of the rotating drum, an absorbent-core
material supplied on an air stream.
<29> A method for manufacturing an absorbent core by using
the fiber stacking device according to the aforementioned item
<26>, the absorbent core manufacturing method including:
[0110] a fiber stacking step of sucking and stacking, in the
collecting/stacking recess of the rotating drum, an absorbent-cote
material supplied on an air stream.
<30> The absorbent core manufacturing method according to the
aforementioned item <28> or <29>, wherein the
absorbent-core material is sucked and stacked in the
collecting/stacking recess while the collecting/stacking recess of
the rotating drum is being transported along a section covered by
the duct. <31> The absorbent core manufacturing method
according to the aforementioned item <29>, including the
steps of:
[0111] obtaining a fiber stack by stacking the absorbent-core
material in the collecting/stacking recess; then further rotating
the rotating drum; sucking the fiber stack onto the mesh belt at a
position in opposition to the vacuum box; transporting the fiber
stack in this state to a section where the transfer roller and the
rotating drum come nearest to one another, or to the vicinity
thereof; releasing the fiber stack from the collecting/stacking
recess by suction from the transfer roller side; and transferring
the fiber stack onto the transfer roller together with the mesh
belt;
[0112] then passing the fiber stack, which has been transferred
onto the transfer roller, on is to a core-wrap sheet that has been
introduced onto the vacuum conveyor arranged below the transfer
roller; and
[0113] then folding back both side sections of the core-wrap sheet
that extend along the transporting direction, and covering the
fiber stack with the core-wrap sheet.
<32> The absorbent core manufacturing method according to any
one of the aforementioned items <27> to <29>, wherein
the absorbent-core material is stacked not only in the openings in
the recess-bottom-surface corresponding section of the outer
shaping member where suction from the bottom surface of the
collecting/stacking recess is performed, but is stacked also on the
opening defining section (the linear members) of the outer shaping
member where suction from the bottom surface is not performed.
<33> A method for manufacturing an absorbent article that
includes an absorbent core and a sheet material to which the
absorbent core is fixed, absorbent article manufacturing method
comprising:
[0114] a step of fixing, onto the sheet material, the absorbent
core obtained by executing the manufacturing method according to
any one of the aforementioned items <27> to <32>.
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